Solve for $a$, $- \dfrac{a + 2}{5a - 10} = \dfrac{1}{4} $
Solution: Multiply both sides of the equation by $5a - 10$ $ -(a + 2) = \dfrac{5a - 10}{4} $ Multiply both sides of the equation by $4$ $ -4(a + 2) = 5a - 10 $ $-4a - 8 = 5a - 10$ $-8 = 9a - 10$ $2 = 9a$ $9a = 2$ $a = \dfrac{2}{9}$